1. Technical Field
This invention relates to the quantitative measurement of the concentration of a particular gas in a gas mixture using the principle of non-dispersive infrared absorption. This invention provides an apparatus for such measurements which in the preferred embodiment includes two or more electrical current-modulated infrared microsources. These microsources eliminate the need for a conventional mechanical chopper for the synchronous detection of infrared radiation and render the gas analyzer completely solid-state with no mechanical moving parts. The low electrical power requirements of the apparatus allow for battery operation.